Significant Association Between Gallstone Disease and Nonalcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis.

BACKGROUND: Gallstone disease (GD) and nonalcoholic fatty liver disease (NAFLD) are common digestive disorders worldwide. Both conditions share certain risk factors including obesity, insulin resistance and diabetes. Several epidemiologic studies have reported the relationship between these two conditions.

AIM: We conducted a systematic review and meta-analysis to characterize the association between GD and NAFLD.

METHODS: A comprehensive search of the databases MEDLINE and EMBASE was performed from inception through November 2015. The inclusion criterion was the observational studies' assessment of the association between GD and NAFLD in adult participants. Pooled odds ratio (OR) and 95 % confidence interval (CI) were calculated using a random-effects model.

RESULTS: Data were extracted from 12 observational studies (9 cross-sectional studies, 1 case-control study and 2 cohort studies). The pooled OR of NAFLD in patients who had GD was 1.55 (95 % CI 1.31-1.82). The statistical between-studies heterogeneity (I (2)) was 64 %. The association remained significant when limited to cohort studies with pooled OR 1.33 (95 % CI 1.14-1.55, I (2) = 0 %).

CONCLUSION: Our meta-analysis demonstrated that GD is significantly associated with NAFLD. Further prospective studies exploring the underlying mechanism of this association should be pursued.